Batting process



Patented Oct. 25,1927. I a 1,646,605

UNITED, STATES PATENT or-Pica.

WILLIAM BURTON 'WESCOTT, OF QUINCY, MASSACHUSETTS, ASSIGNOR TO THE RUB-BER LATEX RESEARCH CORPORATION, OF BOSTON, MASSACHUSETTS, A CORPORA-TION-OF MASSACHUSETTS. i l i I BATTING PROCESS.

No Drawing. Application file 1. 1 ovember 18, 1922. Serial No. 601,911.:

This invention relates to batting processes a t to be brittle. Thesedifiiculties are par- 65 and products thereof; and it comprises aticularly apparent in the case of asbestos I method of obtaining firmbatted fabrics from fibers which do not tend to interlock or formnormally smooth, non-felting fibers,-such as any permanentv union onbatting in water; 5 cotton, flax, jute, woody fibers, asbestos, etc. butthey are also true with many other wherein such fibers are batted inwater to smooth fibers such as cotton. I 60 which is'added during orafter the batting It is the purpose of the present'invention a smallproportion of latex under conditions to produce an open-texturedfelt-like fabric precluding the coagulation of said latex and from thesesmooth fibers; the fabric fibers the batted material is thereafter driedin resembling wool felt in that they are bonded such a manneras toconvert the latex solids together at. meeting faces. Although the 6 intoa homogeneous dried gel, such gel fa ric is not felted in the samemechanical uniting and bonding together at their meet-v way as wool feltyet its characteristics are ing faces the several fibers so batted; andit felt-like; and for the sake of convenience it further comprises asanew material, a tough, 1s herein called felt.- a

strong resilient felt composed of fibers in I have discovered that I canefiect apar- 7 random arrangement, such fibers being bondticularlydesirable type of union between ed together at meeting points by latexsolids smooth fibers in a batted fabric and produce in the form' of adried gel, such gel being this result by the use of'limited amounts ofvulcanized or unvulcanized as the case ma latex; latex being the milkyjuices of cerbe; all as more fully hereinafter set for tam plants. Latexin its natural state is not and as claimed. a articularly stable liquid,readily coagu- There is no particular difficulty in making latmg 1n thepresence of many chemical firm, hard felts by simply batting wool andagents, such as acids, phenols, etc., and by like fibers of irregular orserrated outline a 'tation. It 'an'however be stabilized sufii-.

together in the presence of water. Wool as c1ently for use by thepresence of a little a fiber. has an imbricated surface rendering ammona or other alkaline body. While possible a locking engagement betweenfiber latex is not presumed, because of its susand fiber. It is,however, substantially imcep l nature, o rm t concentration or 0possible to make similar felted materials by purification, I haveiscovered and elsewhere batting together smooth fibers such as'ootdescribed and claimed (application Serial ton, flax, jute, asbestos,etc. While the felt No.. 601,909) that both concentration and made bybatting 'such fibers in water may unfication can be effected bysubmitting have some degree of consistency while the atextocentrifugalaction under certain conmaterial iswet it has little strength afterditions with production of a product of drying. In or, er to make feltsof smooth standardized nature. Either the stabilized fibers it is thecustom to use a greater or ordinary latex or these preparations, whichless proportion of rough fibers, wool or the are more 1n the nature of arubber emulsion, like; and generally the strength of the felt may beused in the present invention.

' 0 is the better the greater the proportion of V In the batted fabricsproduced under the wool or the like therein and the less the propresentinvention ver little latex is necesportion of cotton or smooth fiber. Inorder sary to give a consi erable degree of meto make fabric of anstrength from batted chanical strength and a firm union between smoothfibers in ran om arrangement, it is fiber and fiber. No such proportionis neces- 45 in general necessary to use an adhesive; glue, sary to givefirm union as is required with starch,.etc. Resilient felt cannothowever be adhesives and sizes; and resilient felts can made from battedfibers with the use of subbe produced with these small amounts ofstantial amounts of such sizing materials. latex. B the use of certainexpedients re- Many of these bonding or sizing agents are silient fe tsof varied character can be ro- 50 water-soluble and while they may givea duced. As in the case of wool felts, t ere batted fabric strength in adry condition, is a union between fiber and fiber at their the wetstrength 1s commonly very much crossing or contactin points; this unionless. These materials which are not waterhowever being efiecte a driedgel of soluble, as with some of the rosin sizes, are latex solidsinstead of mec anically as ui'the case of Wool. Dried latex el being butlittle affected by water, and vu canized dried gel notl' at all, the wetstrength of the felt is 11g 1.

Latex can be dried down to give a gel; this gel comprising not only thecaoutchouc of the latex but also the other dissolved and'suspendedsolids (resins, proteids, etc.) as well. .The gel formation isirreversible; the gel once formed not going back into suspension.'iorm's an apparently homogeneous material (unlike rubber formed bycoagulation), this material being of high mechanical strength and ofdesirable properties. In particular it vulcanizesin a desirable way; itsproperties in this respect being more nearly like those of long milledrubber than of raw rubber.

Latex mixes freely with water and tions can be obtained in almost anydesired concentration. Latex usually contains 20 to 30 per cent ofcaoutchouc. In the present invention I ordinarily dilute such a latexsoluto form a considerably weaker liquid.

When diluted,'of course, relatively small amounts of acids or othercoagulants will .suflice to produce a clotting, even as against theinfluence of ammonia.- or other alkali present and'with many of use is'here contemplated, there is enough acidity present in the fiber toneutralize the stabilizing agent of ordinary latex.. As I do not desireany such coagulation in the present invention, I customarily maintain inbatting liquids distinctly" but falntl allialine at the time thelatexisi adde With the rubber emulsions produced by purification of thelatex, with removal of some or most of the non-caoutchouc solids of thelatex, the susceptibility to coagulation by the action of acids is notso great andnot so much care need be exercised in maintaining thebatting materials alkaline as in usmg ordinary stabilized latex.'Thq,amount and the strength of solution used of latex depend uponcircumstances; but I ordinarily and where it is desired to obviateadjust both so as to produce between 1 and 5 per cent of latex solids inmy final dry product. Coagulation of latex is a localized operation andalways produces localized coagulation of a'stringy nature." This is notdesirable since it is my object in the present invention to producesubstantially uniformly distriuted filmiform dried gel-.uponthe fibersthroughout the article. Wherever the fiber is wetted by the latexsolution and then driedQdried latex gel is produced. With 1 such smallamounts of this latex .gel as is contemplated in this invention in anuncompressed felt, the space relations of the fibers remain unchangedbythe present operation; and a resilient felt can gel produced in thefelt is more or less tacky;

The' gel on drying.

the fibers whose l the latex in and on the be produced. The

in the felt. If vulcanization be effected without compression, thevolume relation- Ship of the felted mass remains unchanged. There isproduced a felt with the fibers firmly united at their meeting points,but otherwise in the relation in which they are left by the batting.\Viththe rubber gel in its tacky condition, on compression the volumerelationship can be altered to any extent which may be desired; thatis,a*denser felt can be produced at will. With and vulcanization, thefibers their new relation. Within limits, the compression resilience ofthe felt can be adjusted. as may be desired. Latex though an emulsionhas the property of (infusion to a largeextent and advantage can betaken of this to produce felts with a graded impregnation; one side onlyof the moist batted felt being treated with the latex. This gives amaterial having more of the dried gel, in one face than in the other;and in the latter face there ma" be but little. On brushing or combing,a textured face is produced. In making some classes of goods, aplurality of impregnations may be desirable. For example a batted feltmay be made with the aid of a i-mited amount of latex and the felt driedand vulcanized (without pressure or much pressure) to obviate tackinessof the gel and give a resilient felt. This may then be reimpregnatedfrom one face and then vulcanized under some pressure. The operationproduces a fabric with one side open textured and resilient and theother of denser character. It may be dense, tough and impervious towater.

In the practice of the present invention the fibers may be simply battedtogether in water containing a'small they may be first batted in waterin the usual way and then given a treatment with latex solution, beforeor after drying.

Where'batting is accomplished in the presence of water containing latex,on drying,

into the gel condition. As stated, this gel is irreversible. On furtherdrying, it forms a tough, dry filmiform gel in and on the fibers. Wherea maximum compression resiliency in the final product is des1red,Icommonly subject the felt after drying to a grad ually lowered gas oratmospheric pressure and then allow the pressure to return toatmosphericas rapidly as possible. On slowly owering the pressure, which may remainbetween films of latex gel and the underlying fiber, is'removed; the airand moisture escapin through the inter stitial ducts; On su denlyrenewin the pressure thefilm of dry e1 is pressed firmly againsttheunderlying fi er and. a very good type of bond is secured. It has beencompression are fixed in.

fiber finally passes.

found proportion of latex; or

any air or moisture that an alternation of 2 or 3 of such successivepressure oscillations with slowly lowering pressure and rapidly renewedpressure, etfect a thorough forcing of the rubber gel into the mostintimate contact with the fiber;

A slow reduction of pressure is advantageous and a rapid rencval of thepressure is also advantageous, and particularly in resilient feltedarticles in which it is not desired to obliterate the voids.

Felts made as above described may be subsequently vulcanized or not. Ifnot vulcanized, since the deposited dried rubber gel is more or lesstacky, an applied pressure causes a certain amountof adhesion and mayobliterate or materially lessen the voids thus reducing the compressiveresiliency. If the material be vulcanized Without con'ipression, thistackiness is obviated and a high compressiveresiliency may be obtained.If it be desired to vulcanize the material, a certain amount of fine orcolloidal sulfur may be incorporated in batting at the same time as thelatex. 01' cold vulcanizing agents such as sulfur chlorid may beemployed after drying the bat. Or any other suitable vuleanizingprocess, such as the Peaoheycold vulcanization process may be used.

Where a dense, tough felted mass is desired, the impregnated felt maybe, after thorough drying, cured with vulcanizing agents undermechanical pressure as betweq platens of a press. Sometimes it. isdesirable to introduce inert compounding materials into the battingduring the manufacture. \Vith the latex treatment that of filler withoutforfeiting mechanical strength in the finished product. i

What I claim is the batted fiber will. ordinarily take up a considerableproper- 1. In the felting of; smooth fibers the process whichcomprisesbatting such. fibers, coating and impregnating the battedfibers with latex, drying, and during drying producing a slowly reducedatmospheric pressure.

2. In the felting ofsmooth fibers the process which comprises battingsuch fibers, coating' and impregnating the batted fibers with latex,drying, and during drying alternately producing a slowly reducedatmospheric pressure and quick-and rapid restoration ot atmosphericpressure.

In testimony whereof,'I have hereunto affixed my signature.

WILLIAM BURTON 'WEseoT'r

